Portable elevating apparatus



March 4, 1969 E. P. EMBREE 3,430,734

PORTABLE ELEVATING APPARATUS Filed Aug. 16, 1967 Sheet of 2 INVENTOR.EARL P. EMBREE 2% M- e P ATTORN Y March 4, 1969 E. P. EMBREE 3,430,734

PORTABLE ELEVATING APPARATUS Filed Aug. 16, 1967 sheet 3 or 2 I NVENTOR.

EARL P. EMBREE BY g Y ATTORNEY United States Patent ()fiiice PatentedMar. 4, 1969 2 Claims ABSTRACT OF THE DISCLOSURE A portable elevatingapparatus includes a carriage that slides on a ladder and is controlledin its movement by the operator in the carriage. A hydraulic cylinder ismounted in the carriage and its piston rod has a cable or rope gearingso connected between the carriage and the top of the ladder as to movethe carriage about four or five times as fast as the moving piston rod.The ladder carries a propping pole so that the operator can place theladder near a fruit tree and use the carriage for lifting him todiiferent heights for picking fruit from the tree.

BACKGROUND OF THE INVENTION Field of the invention In the picking offruit, portable ladders are used by the fruit pickers and they climb upand down them while picking fruit at different levels of the tree. Thisis tiring and time consuming. Adding a slidable carriage to the ladderwith a hydraulic operating mechanism will not unduly increase the weightof the portable ladder if a smaller length cylinder is mounted directlyon the carriage and a cable or rope gearing operatively connects thepiston rod to the carriage and ladder so that a movement of the pistonrod will move the carriage about four or five times as fast as thepiston rod. The total weight of the ladder, carriage and operatingmechanism can be less than sixty-five pounds which is not too difiicultor heavy for the fruit picker to carry.

Description of prior art Several patents disclose a ladder with acarriage that can move therealong but the source of power is placed atthe base of the ladder rather than in the carriage. The mounting of thehydraulic power source on the carriage makes the entire mechanism morecompact and lessens the weight of the entire device.

SUMMARY OF THE INVENTION An object of my invention is to provide aportable elevating apparatus in which a carriage is movable along aladder which functions as an elongated carriage guide and supportingmember. The power mechanism for moving the carriage is mounted in itrather than at the base of the ladder. A relatively short hydrauliccylinder is placed on the carriage and a cable or rope and pulleyarrangement operatively connects the piston rod of the cylinder with thecarriage and ladder so that the carriage will move along the ladderabout four or five times the speed of the piston rod.

A further object of my invention is to provide a device of the typedescribed that has a foot and hand control for operation by the operatorwhile he stands on the carriage platform. The device is relativelysimple in construction and is durable and eificient for the purposeintended.

BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 is a side elevation of thedevice and shows the carriage slidably mounted on the ladder.

FIGURE 2 is a front elevation of the device when looking in thedirection of the arrows 22 in FIGURE 1. FIGURE 3 is an enlargedhorizontal section taken through the device substantially along the line33 of FIGURE 1.

FIGURE 4 is a diagrammatic showing of the various parts of the carriageoperating mechanism.

DESCRIPTION OF THE PREFERRED EMBODIMENT In carrying out my invention Iprovide a portable ladder indicated generally at A, see FIGURES 1 and 2,that can be propped into an inclined operative position by a leg or propB. The ladder has a top rung 1 and the upper end of the ladder prop B ispivotally connected at 2 to the top rung at the center thereof forsupporting the ladder in an inclined position as shown in FIGURE 1. Theladder has two channel-shaped sides or runners 3 and 4 which arepreferably made of aluminum in order to be light in weight and yetstrong enough to slidably support a carriage, hereinafter described.Additional spaced apart rungs 5 are arcuate in shape, see FIGURE 3, andhave their ends 5a secured to the outer sides of the runners 3 and 4 inany manner desired such as by welding or rivets. When the ladder A is tobe carried, the prop B is swung down upon the ladder rungs 5 and inorder that the main portion of the prop parallel the runners 3 and 4,the upper portion 6 of the prop is inclined slightly, see FIGURE 1, soas to extend from the uppermost arcuate rung 5 to the straight top rung1 to which the prop is pivoted.

The lower end of the ladder A is supported above the ground C by spacedapart feet '7 and 8, see FIGURES 1 and 2. The foot 7 is curved outwardlyand has its upper end welded or otherwise secured to the runner 3 of theladder while the other foot 8 is also curved outwardly and has its upperend likewise secured to the other runner 4 of the ladder. A bracing bar9 extends between the legs 7 and 8 and is secured to the lower end ofthe ladder A for supporting it above the ground. The lower ends of theoutwardly curved legs 7 and 8, are spaced farther apart from each otherthan are the two elongated runners 3 and 4 of the ladder in order togive a wider support for the ladder.

I slidably mount an operator-supporting carriage on the two elongatedchannel-shaped runners or guide rails 3 and 4- of the ladder A, and thecarriage is indicated generally at D, in FIGURES l, 2 and 3. In theenlarged top view of the carriage in FIGURE 3, it will be seen that ithas a platform 10 for supporting the operator, and it also has aninclined front wall 11 that slidably contacts the front surfaces of theladder runners 3 and 4. The front wall 11 is inclined at an obtuse angleto the platform 10 so that when the ladder is in operative or inclinedposition, as in FIGURE 1, the platform 10 will lie in a horizontalplane. Bracing rods 12 for the platform have their upper ends secured tothe side edges of the front wall 11 and have their lower ends secured tothe side edges of the outer corners 13 of the platform.

The carriage D has a housing indicated generally at E for enclosing mostof the operating mechanism for moving the carriage along the ladder, seeFIGURES 1 and 3. The housing has an outer wall 14 and two parallel sidewalls 15 and 16 that extend between the outer wall and the frontcarriage wall 11. Any means for slidably connecting the carriage D tothe ladder A may be used and I have illustrated in FIGURE 3, the twoside walls 15 and 16 slidably contacting the .inner edges of the channelshaped ladder runners 3 and 4, respectively. Carriage guide shoes 17 and18 in the shape of angle brackets are secured to the outer surfaces ofthe housing side walls 15 and 16 respectively, and slidably contact withthe inner surfaces of the channel-shaped runners 3 and 4, respectively.The housing side walls 15 and 16 slide against the ladder runners 3 and4 and prevent any lateral movement of the carriage with respect to theladder.

I will now describe the mechanism for operating the carriage D, on theladder A. FIGURE 3 shows most of the mechanism contained in the housingE while FIGURE 4 illustrates the different parts of the mechanismdiagrammatically. A small portable engine or motor F has a shaft 19 foroperating a hydraulic pump G and the latter pumps fluid from a tank H toa valve by means of a conduit 20. A second conduit 21 leads from thevalve J to the tank H and returns the fluid to the tank when the valvehandle or lever 22 is in neutral position. The valve J is preferablymounted on the front wall 11 of the carriage D in a position where theoperator can manipulate the handle 22 while standing on the carriageplatform 10.

I provide a foot control for operating the valve lever or handle 22. InFIGURES 2, 3 and 4, I disclose a footactuated member K that can slide orpivot in a horizontal plane on the carriage platform 10. I do notillustrate any particular pivot or guide means for the member K. FIG-URE 4 shows the foot-actuated member K in neutral position. A flexiblecable indicated generally at L operatively connects the member K withthe valve lever 22. The member K receives the toe portion of theoperators foot and when the member is shifted to the right from NEUTRALto UP position, the flexible cable will swing the lever 22 from the fullline position shown in FIGURE 4 into the dotted upwardly inclinedposition shown in the same figure. I will explain hereinafter how thismovement of the foot actuated member K will cause the carriage D, tomove upwardly on the ladder A. When the member K is moved to the left inFIGURE 4 from NEUTRAL to DOWN position, the valve lever 22 will be swunginto the other dotted line position and the carriage will movedownwardly on the ladder. FIGURES 2 and 3 show the flexible shaft L asbeing disposed on the front face of the carriage wall 11, but it couldbe disposed in the housing E.

The hydraulic mechanism for moving the carriage on the ladder comprisesa cylinder M that is mounted in the housing B, see FIGURES 3 and 4. Apiston 23 is slidably mounted in the cylinder and a piston rod 24extends from the piston and out through the lower end of the cylinder.The free end of the piston rod 24 carries a cross head 25 that has apulley or sheave rotatably mounted at each end thereof. A cable or rope26 has one end secured to the cylinder M, at 27, and is then passedaround one of the pulleys 28, carried by the cross head 25. An idlerpulley 29 is rotatably carried by the cylinder M, and the cable 26 ispassed over this pulley. From here the cable is passed around the otheridler pulley 30, mounted on the cross head 25, and then the cableextends up to the top rung 1 of the ladder A, and is secured thereto at31, see FIGURE 2. The pulleys 28, 29 and 30 and the man ner of passingthe cable or rope 26 around them and securing the rope ends to thecylinder M, at 26 and to the top rung 1 of the ladder forms a ropegearing arrangement that will provide a ratio of about four-to-one inmoving the carriage D, faster than the moving piston rod. A conduit 32,see FIGURE 4, extends from the valve J to the top of the cylinder M.

OPERATION the foot control member K for moving it to the right in FIGURE4, for swinging the valve handle 22 into UP position or he can actuatethe handle by hand.

The engine F operates the pump G and the latter will withdraw fluid fromthe tank or reservoir H and send it through the conduit 20 to the valveJ. If the valve handle 22 is in NEUTRAL position, the fluid will returnfrom the valve to the reservoir H by the conduit 21. As soon as theoperator swings the valve handle 22 into UP position either by his handor by manipulating the member K with his foot, the fluid will flow intothe top of the cylinder M by means of the conduit 32 rather than flowback into the reservoir through the conduit 21. The fluid in thecylinder will force the piston 23 and the piston rod 24 downwardly withrespect to the cylinder and the piston rod will force the pulleys 28 and30 against the looped portions of the cable 26, see FIGURE 4. Since oneend of the cable or rope 26 is anchored to the cylinder =M, at 27 andthe other end is secured to the top ladder rung 1 at 31, the loopedportions of the cable around the pulleys 28 and 30 and around the idlerpulley 29 on the cylinder M, will cause both the piston rod 24 and thecylinder to move upwardly along the ladder A, the cylinder moving aboutfour times as fast as the piston rod and carrying the carriage Dupwardly therewith. The length of the stroke of the piston rod 24 in thecylinder is predetermined so that when the piston 23 reaches the bottomof the cylinder M, the cylinder will have moved the carriage to the topof the ladder A.

The operator can stop the upward movement of the carriage D, along theladder A, at any place desired by merely swinging the valve handle 22,back into NEU- TRAL position. This will stop further flow of fluid intothe cylinder M, and instead the pump G will force the fluid from thevalve 1, back to the reservoir H, by means of the conduit 21. Thetrapped fluid in the cylinder top will hold the carriage D at the levelto which it has been raised on the ladder.

When the operator wishes to descend to any level on the ladder, heswings the valve handle 22 into DOWN position or he moves his footmember K to the left in FIGURE 4. This will cause the valve J to permitthe reverse flow of fluid from the cylinder M, through the conduit 32,valve J, and conduit 21, back to the reservoir or tank H. The weight ofthe carriage and operating mechanism is suflicient to force the piston23 upwardly in the cylinder M to force the fluid back through theconduit 32 when the valve handle 22 is in DOWN" position. The speed ofdescent is controlled by the amount of fluid the valve I will permit toflow from the cylinder into the valve and on through the conduit 21 tothe reservoir or tank 4. The conduit 21 is large enough in capacity toalso receive the fluid from the valve I, that has entered it from theconduit 20, because the engine F, and pump G, are continuously operatingduring the downward movement of the carriage -D, and the reverse flow offluid in the conduit 32.

When the ladder A is held in operative position by the prop or laddertongue B, the top of the ladder will be about twelve feet above theground. The ladder has a width of about sixteen inches although I do notwish to be confined to any exact measurements. Most of the parts will bemade of aluminum so as to make the device light in weight. A two andone-half or a three horsepower engine F, is suflicient to operate thehydraulic mechanism. The four-to-one speed ratio produced by the idlerpulleys and cable or rope 26 will move the carriage D, so that at notime will the piston rod 24 and pulleys 28 and 30 strike the ground C.The height of the carriage front wall 11 is about thirty-six tothirty-eight inches high and this will permit the operator to leanagainst the wall while standing on the platform 10 during the picking offruit from a tree.

A smaller length cylinder M, may be used when it is mounted on thecarriage D, than when the cylinder is mounted on the ladder A. Alsothere is less length for the controls when the carriage liftingmechanism is all mounted in the carriage rather than placed on theground. The speed of moving the carriage D, on the ladder A, isincreased by the use of the idler pulleys and the manner of passing thecable or rope 26 around them so as to provide a fouror five-to-oneratio. A fruit picker is handicapped in having to continually climb upand down a ladder while picking the fruit. It is both tiring to thepicker and slows him down in his work. The hydraulically moved carriagewill lift the picker more quickly than he can climb the ladder and withno physical effort on his part.

I claim:

1. A portable elevating apparatus comprising:

(a) an elongated carriage guide and supporting member including a pairof spaced apart and parallel guide rails;

(b) spaced apart rungs interconnecting said guide rails and beingarcuate-shaped in parallel planes that extend at right angles to thelengths of said guide rails;

(c) an elongated prop having an end pivotally connected to an end ofsaid supporting member for holding the latter at an upwardly inclinedposition with respect to the ground;

(d) a carriage slidably mounted on said guide and supporting member andhaving a platform and a front wall, the latter lying adjacent to a planein which said guide rails lie;

(e) hydraulic means supported by said carriage and moving through thespaces afforded by the arcuateshaped rungs when the carriage moves alongsaid guide rails, said means including a cylinder and piston rod whosecommon axis parallels the lengths of said guide rails, the piston rodmoving downwardly with respect to the cylinder and carriage as the rodis moved out of the cylinder;

(f) rope-geared means interconnecting the carriage, piston rod and saidguide and supporting member for lifting said carriage along said guideand supporting member faster than said piston rod moves downwardly withrespect to said cylinder so that the piston rod will have a relativeupward movement with re spect to the guide rails as the carriage movesupwardly from its initial starting position; and

(g) valve-controlled means for directing fluid into and out from saidcylinder for moving said piston rod with respect to said cylinder,whereby said carriage is moved.

2. The combination as set forth in claim 1: and in which (a) a portionof said elongated prop, that lies adjacent to the end pivotallyconnected to said supporting member, is inclined at an angle to theremaining part of the prop so that this remaining part can contact withthe arcuate portions of said rungs and lie parallel with said guiderails when said prop is swung into inoperative position preparatory totransporting the device.

References Cited UNITED STATES PATENTS 2,538,517 1/1951 Hayden 187262,931,461 4/ 1960 Lawson 187-26 3,127,952 4/1964 Baerg 187-14 FOREIGNPATENTS 1,157,310 5/1958 France.

1,015,255 12/ 1965 Great Britain.

RICHARD E. AEGERTER, Primary Examiner. HARVEY C. HORNSBY, AssistantExaminer.

US. Cl. X.R.

